The present invention relates to reclining chairs and more particularly to a rocker mechanism for a reclining chair.
Rocking-type chairs typically include a rocker spring mechanism disposed between a stationary base and lower structure of a chair frame for biasing the chair in an upright, neutral position while enabling the chair to rock forwardly and rearwardly. As a seat occupant rocks, the chair follows the contour of a rocker mechanism. Traditional rocker mechanisms generally include a spring box design including two opposed panels linked together with a rod that provides a pivot for the two panels for forming a xe2x80x9crocker boxxe2x80x9d. To provide control and support for relative rocking motion between the opposed panels, a plurality of coil springs are contained within the rocker box, resiliently interconnecting the opposed panels. Forward and rearward rocking causes compression and elongation of the various springs.
There are several disadvantages associated with traditional rocker mechanisms. One of these includes limited rocking motion as a result of a limited rocking radius. In order to achieve a larger rocking radius, traditional rocker mechanisms must be increased in size. The distance between the opposed panels must be increased and longer springs implemented within the rocker box. Further, traditional rocker mechanisms typically implement metal coil springs for providing resiliency. The nature of such springs, as well as their interaction with other components of the rocker mechanism, results in undesirable noise as the rocker mechanism is caused to function. Finally, traditional rocker mechanisms tend to include a significant amount of components. The number of components increases manufacturing complexity, and therefore manufacturing cost, in addition to increasing component cost.
Therefore, it is desirable in the industry to provide an improved rocker mechanism. The improved rocker mechanism should eliminate the disadvantages associated with prior rocker mechanisms, including noise and limited rocking motion. Further, the improved rocking mechanism should be more compact and less complex for reducing overall cost.
Accordingly, the present invention provides a rocker mechanism adapted for operably interconnecting a chair to a base. The rocker mechanism includes an upper casting adapted for interconnection with the chair, a lower casting adapted for interconnection with the base and a leaf spring interconnecting the upper and lower castings. The leaf spring is secured to the upper and lower castings in such a manner that the rate of the spring varies as a function of the direction of rocking. The leaf spring includes first and second effective lengths defining first and second effective spring rates, thereby providing a dual-rate leaf spring. The first effective length of the first leaf spring is defined as a distance between a spring seat face of the upper casting and a spring seat face of the lower casting. The second effective length of the first leaf spring is defined as a distance between connection points of the first leaf spring to the upper casting and the lower casting.
The present invention further provides a rocker mechanism adapted for operably interconnecting a chair to a base including an upper casting, a lower casting, and first and second leaf springs interconnecting the upper and lower castings for relative rocking motion therebetween, whereby the first and second leaf springs extend angularly between the upper and lower castings for maximizing the length of each of the first and second leaf springs.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.